President Barack Obama travelled to Cairo in June 2009 to promise a new beginning between the US and the Muslim world based on “mutual interest and mutual respect”. In The Future of Islam, John Esposito has written the handbook for this new age of engagement. Intolerant of the extremists bent on provoking a clash of civilisations – western Islamophobes and violent Islamists alike – Esposito’s book is a calculated appeal to the moderate middle ground upon whom the success of Obama’s policies depends.

Esposito is the right man for the job: he is a leading scholar of modern Islam, with more than 35 books on the subject to his credit, and heads a centre for Christian-Muslim understanding at Georgetown University. In the course of a long and distinguished career, he has come to know the leading Islamic scholars of our age, who have shaped his sympathetic engagement with Islam and its reformers. His lifelong study of religion has left Esposito convinced that Islam is like any other faith, and he has dedicated himself to undermining assumptions of “Islamic exceptionalism”. He argues that what moves Muslims is not unlike what moves Christians and Jews alike.

The book opens with an introduction to Islam for the lay person, setting out the basic tenets of the faith. Esposito goes to great pains to break down preconceptions of Islam as a monolithic faith. Most of the world’s 1.3bn Muslims live in 57 countries across Asia, the Middle East and Africa, in which Muslims comprise the majority of the population. The geographic spread of Islam as a global religion has meant great diversity in worship and beliefs – not one Islam but many Islams.

In the 20th century, large and expanding Muslim minority communities have emerged in western Europe and the US. Islam is now the third-largest religion in North America, and the second-largest faith in Europe, where the Muslim population has grown from 12m to 20m over the past decade. The growing Muslim presence in Europe and North America makes a mockery of geographic divides such as “the west” and “the Muslim world”. Obama needs to take on board the welfare of Muslims in the US as much as addressing the political concerns of Muslims in Asia and Africa for his appeal to succeed.

The expansion of Islam’s presence in the west has not led to greater acceptance or understanding. In 1997, the Runnymede Trust, a British think-tank, coined the expression “Islamophobia” to capture the growing animosity towards Muslims in the west. It is, Esposito maintains, as dangerous to western civilisation as anti-Semitism and it should be fought with as much determination.

Esposito turns to the role of Islam in politics. Beginning with Iran’s 1979 Islamic Revolution, he examines Islamist politics from the fully democratic Justice and Development Party, now ruling Turkey, to the Jihadi Islamists who engage in terror tactics to advance political ends. He explores how America’s inconsistency in promoting democracy in the Muslim world, and unwavering support for Israel’s use of force against its Arab foes, have served to encourage the anti-Americanism of many radical Islamist groups.

For many in the west, Islam represents a medieval theology, ill-suited for modern times. What Islam really needs, they go on to argue, is a Reformation leading to an Enlightenment and a separation between religion and state – as though all faith communities were condemned to repeating Christian Europe’s experience, with all the bloodshed and intolerance that it entailed. Where, they ask, are the Muslim Martin Luthers of today?

Esposito believes the question is misguided, suggesting that Islam is static and there are no Muslim reformers at work. He argues reformist Islam has a long and illustrious tradition that is alive and well. “The number and diversity of today’s reformers belie the oft-raised question (with its implied scepticism) ‘Are there any Muslim reformers?’ I could wish there were fewer, because I would not have faced the difficulty of selecting a representative sample.”

The most fascinating and original material in the book is in Esposito’s treatment of Islamic reformers today from both Muslim majority countries and Muslim minority communities in the west, engaged in debates that are setting the agendas for Islam in the 21st century.

Several engaging personalities emerge from Esposito’s “representative sample”. In 2005, Amina Wadud, a Muslim convert in New York, broke a 14-century taboo and became the first woman to lead a mixed congregation of men and women in Friday prayers. A devout Muslim and feminist, Wadud has termed her decades-long struggle for women’s rights as a “gender jihad”.

Amr Khaled, an Islamist televangelist from Egypt, attracts more hits on his website than Oprah Winfrey. “Khaled blends conservative religious belief with a charismatic personality and speaking style,” Esposito explains, “Western self-help, management-training jargon, and an emotive crowd-pleasing performance full of stories, laughter and tears.”

And then there is Muslim reformer Tariq Ramadan. He is defining a new notion of identity for European Muslims and drawing on the experience of Muslims in Europe to propose reforms for Muslim majority countries. In this sense, the west has a contribution to make towards the reform movement in Islam. “Muslims in the west,” Esposito concludes, “have been a resource in the development and dissemination of models for reform, from fresh religious interpretations of the Koran and Islamic tradition to their applications on issues of democratisation, gender equality, human rights and religious pluralism.”

In Esposito’s analysis, Islam needs no Reformation: reformers are at work in all corners of the Muslim world. The need for change is in the west itself. Recognition of a shared Judeo-Christian heritage was key to combating anti-Semitism after the second world war. The fight against Islamophobia will only be engaged when the west recognises “that the Children of Abraham are part of a rich Judeo-Christian-Islamic history and tradition”. Through his scholarship and engaging writing, Esposito proposes the way forward for a better future for both Islam and the west.

Eugene Rogan is director of the Middle East Centre, University of Oxford. He is author of ‘The Arabs: A History’ (Allen Lane)